Warn if using unnamed diversion.

* lib/m4sugar/m4sugar.m4 (_m4_divert, m4_divert_push): Add
optional parameter, which controls warning.
(m4_divert_pop, m4_cleardivert, m4_divert_require)
(_m4_require_call): Adjust callers.
* lib/m4sugar/m4sh.m4 (AS_REQUIRE): Likewise.
* tests/m4sh.at (AT_DATA_LINENO): Avoid triggering the warning.
* tests/m4sugar.at (AT_CHECK_M4SUGAR_TEXT, m4@&t@_append)
(m4@&t@_text_wrap, recursion): Likewise.
(m4@&t@_warn, m4@&t@_divert_stack): Adjust expected output.
* tests/tools.at (autom4te and whitespace in file names)
(autoconf: the empty token): Avoid triggering the warning.
(autoconf: AC_PRESERVE_HELP_ORDER): New test.
* tests/mktests.sh (ac_exclude_list): Retire prior test.
* NEWS: Document the warning.
* doc/autoconf.texi (Redefined M4 Macros) <m4_divert>,
<m4_undivert>: Make even more explicit that using these directly
is discouraged.
(Diversion support): Further warn against improper diversion
changes.
<m4_divert_text>: Give an example of proper use.
Reported by Mike Frysinger.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 39 insertions, 4 deletions

diff --git a/tests/tools.at b/tests/tools.at
index e23ac04d..aa3f2585 100644
--- a/tests/tools.at
+++ b/tests/tools.at
@@ -164,7 +164,7 @@ do
 
   cat >"$file" <<'END'
 [m4@&t@_init[]m4@&t@_include(foo.m4)
-m4@&t@_divert(0)d@&t@nl
+m4@&t@_divert([])d@&t@nl
 FOO]
 END
   cat >"$dir"/foo.m4 <<'END'
@@ -186,7 +186,7 @@ END
   cat >"$file" <<'END'
 [m4@&t@_init[]m4@&t@_include(foo.m4)
 m4@&t@_pattern_forbid([^bar$])
-m4@&t@_divert(0)d@&t@nl
+m4@&t@_divert([])d@&t@nl
 FOO]
 END
   rm -rf "$outfile" "$cachedir"
@@ -196,7 +196,7 @@ END
 
   cat >"$file" <<'END'
 [m4@&t@_init[]m4@&t@_include(foo.m4)
-m4@&t@_divert(0)d@&t@nl]
+m4@&t@_divert([])d@&t@nl]
 END
   rm -rf "$file.m4f"
   AT_CHECK_AUTOM4TE([-C "$cachedir" -I "$dir" --language=m4sugar --freeze -o "$file.m4f" "$file"])
@@ -464,7 +464,7 @@ AT_SETUP([autoconf: the empty token])
 
 AT_DATA_M4SH([configure.ac],
 [[m4_init[]m4_pattern_allow([^foo$])
-m4_divert([0])dnl
+m4_divert([])dnl
  line that begins with a space
 ]])
 
@@ -535,6 +535,41 @@ AT_CLEANUP
 
 
 
+# autoconf: AC_PRESERVE_HELP_ORDER
+# --------------------------------
+AT_SETUP([autoconf: AC_PRESERVE_HELP_ORDER])
+AT_KEYWORDS([m4@&t@_divert_text])
+
+AT_DATA_AUTOCONF([configure.ac],
+[[AC_INIT
+AC_PRESERVE_HELP_ORDER
+AC_ARG_WITH([one], [  --with-one])
+AC_ARG_ENABLE([two], [  --enable-two])
+m4_divert_text([HELP_ENABLE], [arbitrary $text])
+AC_ARG_WITH([three], [  --with-three])
+AC_OUTPUT
+]])
+
+AT_CHECK_AUTOCONF
+AT_CHECK_CONFIGURE([--help], [], [stdout])
+AT_CHECK([sed -n '/^Optional/,/^$/p' stdout], [],
+[[Optional Features and Packages:
+  --disable-option-checking  ignore unrecognized --enable/--with options
+  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
+  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
+  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
+  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-one
+  --enable-two
+arbitrary $text
+  --with-three
+
+]])
+
+AT_CLEANUP
+
+
+
 ## --------- ##
 ## ifnames.  ##
 ## --------- ##